Publication Date:
2017-09-30
Description:
Knowledge of rheology can reduce damage caused by debris flows, providing a means to delineate hazard-prone areas and to estimate the dangerous effects of these phenomena. The application of numerical models of debris-flow propagation and deposition for hazard prediction requires detailed topographical, hydrological and rheological data, which are not always available. The large Rivoli Bianchi Fan on the Eastern Italian Alps is mainly built from sediment transported by debris flows along the Citate Torrent and its tributaries. We compared the results of numerical simulations performed with two different single-phase, non-Newtonian, two-dimensional models, FLO-2D and IDRA2D-DF, to test their reliability in simulating the behaviour of debris flows on alluvial fans. Data from field topographic surveys and from rain gauges were used as input for the boundary conditions, referring to the Rivoli Bianchi Fan as an example location. The commercial FLO-2D model creates a more accurate representation of the hazard-prone zone in terms of flooded area, but the results in terms of runout distances and deposit thickness are similar to those obtained through the open-source IDRA2D-DF. Parameters obtained through back analysis with both models can be cautiously applied to predict hazard in areas of similar geology, morphology and climate.
Print ISSN:
0305-8719
Electronic ISSN:
2041-4927
Topics:
Geosciences
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